A wireless network in which plural wireless communication devices composing the network perform ad-hoc communication is described in Japanese Patent Unexamined Publication No. 2003-229869, for example. FIG. 19 illustrates the wireless communication method described in the literature.
In FIG. 19, wireless communication devices 1 through 4 form a wireless network and directly communicate with each other without a control station provided. For example, wireless communication device 2 (1902) transmits management information in which reception timing information indicating a start position for receiving the self information, reception window information, and reception cycle information are described, along with a notification cycle for the management information being set. Wireless communication device 1 (1901) that has successfully received this management information stores the reception timing, reception window, and reception cycle, associating them with the communication device number of the corresponding wireless communication device 2 (1902). Then, wireless communication device 1 (1901), when transmitting information, determines a reception start position for the corresponding wireless communication device 2 (1902) according to the reception timing, reception window, and reception cycle of the other end of communication, and transmits the information at the timing.
Here, every wireless communication device transmits a beacon in management information exchange area (hereinafter, referred to as “beacon period”) 1903 in a superframe to exchange management information.
However, as a result that the wireless network moves to which these wireless communication devices 1 through 4 belong, a beacon in a beacon period may collide with another beacon transmitted from a wireless communication device in another wireless network.
If a beacon period thus overlaps that of another wireless network, wireless communication device 1 to 4 determines a beacon period that does not overlap another one, according to offset information received in a beacon period of a group forming another wireless network, and propagates the information to its own wireless network. Then, the wireless communication device 1 to 4 needs to shift to a new beacon period one after another after propagating the information to all the other wireless communication devices in the group.
However, a wireless network with ad-hoc communication is to be distributed-managed and is a network system that establishes itself even if it geographically expands infinitely. Accordingly, it has been difficult to assure that information in a new beacon period is propagated to all the wireless communication devices in the group to which they belong as long as wireless communication device 1 to 4 waits for some counts.